Plumb rod device



Oct. 19, 1937. F. H. HIGGINS. JR

PLUMB ROD DEVICE Filed Dec. 1o, 1936 ITI/.m95 M Patented Oct. 19, 1937 UNHTED STATES @ATENT OFFICE 4 Claims.

This invention relates to a plumb rod device and is designed primarily as a replacement for the conventional plumb bob used on an engineers transit.

5,; It is aimed to provide a structure which is especially adapted for use in windy weather without objection, although functioning equally well in all kinds of weather. As is well known, plumb bobs cause excessive gyration in windy weather on an engineers transit. In my construction, -the device is capable rof transfer to other instruments and without special adjustment,

It is further aimed to provide a no-vel calibrated level rod for the purpose of. indicating the height of the telescope relative to a certain station.

Another object is to provide a novel socket joint enabling ready detachment of the ro-d from the instrument for use as an auxiliary range pole.

20,. The structure permits an instrumentman with another instrument to take a center line on the instrument to which it is attached.

The more specific objects and advantages will become apparent from a consideration of the 25, description following taken in connection with accompanying drawing illustrating an operative embodiment. f

In said drawing:-

Figure l is a view in side elevation showing 30 .the invention in use;

Figure 2 is an enlarged view of the plumb rod device, partly in section and partly broken away to disclose details;

Figure 3 `Ais a detail section taken on the line 3 3 of Figure 2;

on the line 5. 4 or" Figure 2;

Figure 5 is a vertical section taken on the line 5 5 of Figure 2, and

Figure 6 is a cross section taken on the line 6 6 of Figure 2.

Referring specifically to the drawing wherein like reference characters designate like or similar parts, i5 designates a conventional telescope 45 device extending above a table II having legs I2 pivotally and foldably connected theretoas at i3.

The plumb rod has a hollow or tubular rod section if; and a solid rod section i5 adjustably telescoped therein and maintained in different ad- 50 justinents or positions through the medium of a winged screw l5.

A screw member Il passes through the table Si and is detachably screw threaded into the telescope device I5. Such screw member I'I at the lower end has a ball I8 detachably coupled to Figure 4 is a detail longitudinal section taken member 22 therein. 10.

The level rod l5 has suitable calibrations thereon as at 23 reading for instance in feet, tenths of feet and hundredths of feet in an upward direction for the purpose of giving or indicating the height of the telescope above a certain sta- 15,

tion or location such as that indicated at 24 in Figure l.

In order that the calibrations 25 may be read, an elongated slot or opening 25 is provided through the tubular rod Ill, and adjustably telescoped over the tubular rod Ill is an indicator rod or sleeve which has a longitudinal slot, window or opening 2T registering with that at 25, and into which an indicator 2B extends, which is an integral part of the sleeve 2E. Such sleeve 26 is 25 longitudinally slidable on the tubular rod I4 for adjustment and it has elongated slots at 29 through which set screws 3S pass and which are adjustably threaded in openings of the tubular rod i4. The sleeve 26 in effect becomes a part of the rod-I4 and the indicator 28 co-acts with the calibrations as they appear opposite the same.

On the rod I4, above the sleeve 26 a bracket 3l is mounted, which mounts on one side of the rod I4, a level vial 32, the other side or end of the bracket 3l being a counterweight. This level vial is preferably of the watch glass type and the counterweight or counterbalance 3| is necessary in the event the operator wishes to allow the rod to swing free so as to assume a vertical position.

In addition to the advantages attained by the structure as hereinbefore described, a further, andin fact, a primary object of the invention, is the provision of a stationary or fixed object that affords means for erecting a transit at the point desired in the quickest and most expeditious manner. In such use of the device the set screw l is loosened to permit rod section I5 to move freely in the tube It. The transit is then arranged approximately over the mark or monument and the free end of ro-d section I 5 is placed on the mark. The level vial 32 will then show in what direction the transit must be moved to bring it perpendicular to the mark and thus Il i tachment from said ball, spring means carried by avoid the present practice of tests and trials with a plumb bob to position the instrument.

The socket joint at I8 enables the rod to be easily disconnected from the instrument and used as an auxiliary range pole.

The rods I4 and I5 are preferably made of brass tubing and the ball I8 is preferably made of bronze.

Various changes may be made Within the spirit and scope of the invention since it is to be understood that the illustration and specic description relates only to one example or embodiment, it being clear that the invention may equally well be used on transits, levels, plane-tables, other surveying instruments, or Vthe equivalent. Y

I claim as my invention:-

1. An instrument of the class described having a telescope, a plumb rod device depending therefrom, means having detachable connection between the telescope or the like and the plumb rod device to enable use of the latter as an auxiliary range pole, said means of detachable connection comprising a securing member attached to the telescope and having a ball, the plumb rod device having a part formed -With a slot at its one end permitting the quick engagement With and detachment from said ball, spring means carried by the plumb rod device urging said ball into contact with the part, a means on the plumb rod device for taking the reaction thrust of said spring, a bracket on the plumb rod device, a levelling vial on said bracket, said bracket having a countervveight portion on the side of the device opposite to the vial.

2. An instrument of the class described having a telescope, a plumb rod device depending therefrom, means having detachable connection between the telescope or the like and the plumb rod device to enable use of the latter as an auxiliary range pole, said means of detachable connection comprising a securing member attached to the telescope and having a ball, the plumb rod device having a part formed with a slot at its one end permitting the quick engagement with and dethe plumb rod device urging said ball into contact With the part, a means on the plumb rod device for taking the reaction` of said spring, a bracket on the plumb rod device, a levelling vial ion said bracket, said bracket having a counter- Weight portion on the side of the device opposite to the vial, said plumb rod device having a tubular section provided with a window opening, a section telescoped in the tubular section having calibrations registrable with the Window opening, a sleeve on the tubular section having a Window registering with the first mentioned window for reading the calibrations aforesaid through said Window opening.

3. An instrument of the class described having a telescope, a plumb rod device depending therefrom, means having detachable connection between the telescope or the like and the plumb g rod device to enable use of the latter as an auxiliary range pole, said means of detachable connection comprising a securing member attached to the telescope and having a ball, the plumb rod device having a part formed with a slot at its one end permitting the quick engagement with and detachment from said ball, spring means carried by the plumb rod device urging said ball into contact with the part, a means on the plumb rod device for taking the reaction thrust of said spring, a bracket on the plumb rod device, a levelling vial on said bracket, said bracket having a counterweight portion on the side of the device opposite to the vial, said plumb rod device having a tubular section provided With a Window opening, a section telescoped in the tubular section having calibrations registrable with the Window opening, a sleeve on the tubular section having a Window registering with the iirst mentioned window for reading the calibrations aforesaid through said Window opening, said sleeve having an integral indicator thereon co-acting'with the calibrations, said sleeve also having elongated slots therethrough and fastenings passing through said elongated slots and into said tubular rod section.

4. A plumb rod device of the class described comprising a tube, a calibrated rod member slidably adjustable in said tube, said tube having a Window opening enabling observation therethrough of the calibrations on the rod, a sleeve surrounding the tube adjustable therealong and having a Window registrable with the Window opening and bearng an index against which the calibrations upon the rod may be read, said window permitting the reading of the calibrations through said window opening.

FRANK H. HIGGINS, JR. 

